I think there was some hypothesis that in the 4th dynasty these pyramids were enveloped in gold and silver plating. The reason why they are in that state is from future dynasty ransack anything that was not glued. So maybe their is not such an accurate indication of when it was built or how it long it took because it over 5 millennia. If you think of how hard it is to keep track of history that not even millennia old such as the literary works of Geoffrey Chaucer. I mention this detail because his works are incomplete and even historians are unsure they exist or are lost to history. So anyway I do admit this is a great way to engage people and it is great post. Hopefully I added value to this discussion.